Locking connector



Jan. 10, 1961 J. F. HEALY 2,958,017

LOCKING CONNECTOR Original Filed March 7, 1952 "ATTORNEY-S United StatesPatent LOCKING CONNECTOR Joseph F. Healy, Westport, Conn., assignor toHarvey Hubbell, Incorporated, Bridgeport, Conn., a corporation ofConnecticut Original application Mar. 7, 1952, Ser. No. 275,400,

now Patent No. 2,871,456, dated Jan. 27, 1959. Divided and thisapplication Apr. 29, 1958, Ser. No. 733,778

'3 Claims. (Cl. 339-88) This invention relates to an electricalconnector comprising a plug member and a receptacle member which whenjoined may be locked together.

It has for an object to provide a cord connector which may be lockedtogether in such a manner as to prevent inadvertent separation, whichwould thereby cause a break in the circuit.

It has for a further object to provide a means for making contactbetween the electrical contacts of the plug and receptacle when the plugis inserted into the receptacle without the plug and receptacle beingnecessarily locked together, and will maintain this contact when theplug and receptacle are locked. Thus the making and breaking of thecircuit occurs when the plug is inserted into the receptacle and removedtherefrom, and prevents objectionable arcing between the contacts, whichwould be damaging to the contacts.

With the foregoing and other objects in view, I have devised theconstruction illustrated in the accompanying drawing forming a part ofthis specification. It is, however, to be understood the invention isnot limited to the specific details of construction and arrangementshown, but may embody various changes and modifications within the scopeof the invention.

This application is a division of my prior application Serial No.275,400, filed March 7, 1952, for Locking Connector, now Patent No.2,871,456.

In the drawing:

Fig. 1 is a longitudinal section of the device showing the attachmentplug or cap inserted in the receptacle;

Fig. 2 is a side view of the plug or cap portion with the cover insection to show detail;

Fig. 3 is a view looking toward the bottom of Fig. 2;

Fig. 4 is a cross section taken substantially on line 4-4 of Fig. 1; v

Fig. 5 is a sectional view showing a plug contact in elevation as it isengaged by the body portion of the receptacle;

Fig. 6 is an end view of the receptacle showing the entrance slots forthe contact blades of the plug;

Fig, 7 is a lower or inner end View of the upper member of theinsulating body of the receptacle;

Fig. 8 is a view looking from the bottom of Fig. 1 with the metal shellor casing removed; and

Fig. 9 is a top plan view of the lower insulating body member of thereceptacle portion, showing the receptacle contacts.

Referring to Figs. 1 to 9, the device shown therein comprises a plug orcap member 1 and a receptacle member 2. The plug or cap 1 comprises asubstantially cylindrical body 3 composed of a molded plastic or othersuitable insulating material. Lead wires 4 from the cable 5, whichenters the body 3 through a hole 6 at substantially its center, areconnected to contacts 7 by a suitable means, such, for example, as beingclamped by the heads of the binding screw 8 to one leg or the base plate9 of the contacts 7. The contacts 7 are held in an upright position tothe body 3 by means of inserts such as rivets 10 molded into the body 3and the ends inserted into holes in the leg 9 of the contacts and turnedover. The inner or lower end of the body is recessd, as shown at 3a inwhich bases 9 of the contacts are mounted, thus providing an insulatingflange or rim 3b at the outer edges of these plates. The contacts 7 havewidened free end portions 11 with an overhanging hook element 12, theportions 11 being curved, as shown in Fig. 3, with the axis of the plugas a center to enter the corresponding curved slots 13 in the face ofthe receptacle body 14. The receptacle body is made of two members ofmolded insulating material, the upper member 1411 and the lower member14b connected and held together by the screws 14c extending throughlongitudinal passages or openings in the body members and threaded intothe end wall of shell 29, as shown at 14d. These screws therefore alsoretain the shell or casing on the body members. As the plug contacts 7are inserted into the curved slots 13, they engage spring contacts 15 inthe receptacle body which are in a position immediately below orinwardly of the slots 13. Contacts 15 comprise an upright leg 16 curvedat the top, as at 17, to form spring contacts to engage the cap contacts7 as they enter the receptacle body. They are connected by suitablemeans, such as rivets 18, to legs 19 which project from the bindingplate 20. These members 19 extend through and are molded in thetransverse wall 14c of the lower member 14b of the body 14, and areanchored therein by the material of the body entering transverseopenings 19a in these members. Lead Wires 21 from the connecting cable22 are secured one to each of the binding plates 20 by means of beingsecured and clamped beneath the head of a binding screw 23 which isscrewed into a tapped hole in the binding plate 20. Springs 24 which areplaced over and grip nibs 25 in the connector body 14- and which arepartially encased by a well portion 26, are in a position immediatelybelow the curved openings 13 in the body 14. Thus, as the contacts 7 areinserted into the openings 13 they engage the contacts 15 and alsoengage and compress the springs 24. Then, as the cap or plug and thereceptacle portions are relatively turned, the contacts 7, stillmaintaining contact with the contacts 15, are turned so that the hookelements 12 will come into alignment with recesses 27, and as the plugis released will enter and seat under action of springs 24 into recesses27 in the upper surface of the body 14 at a position just beyond andspaced a short distance from the end of the slots 13, see Fig. 7. Thesprings 24 thus hold the contacts 7 in the locked position until suchtime as the cap 1 is pressed downwardly so that the hook portions 12 arereleased from the pockets 27 and the cap 1 may then be rotated in theopposite direction and the contacts 7 removed from the receptacle 2.

To provide a strong protective outer casing the bodies 3 and 14 areencased in shells 28 and 29 respectively, the shells 28 and 29 beingcomposed of metal or other suitable material. The shell 28 is providedwith a flange portion 28a with the lip 30 rolled over, as shown in Figs.1 and 2, so that when the cap 1 is inserted into the receptacle 2, theflange 28a will encase the upper portion of the receptacle 2. Theoverlap or telescoping of the two shells is sufiicient to allow for theneeded longitudinal movements between the plug and body members andstill maintain this overlap and prevent entrance of foreign particles.It is clear that with this construction the cap 1 and receptacle 2 arelocked securely together and cannot be separated unless purposely doneso by the operator. It is also clear that the contacts 7' and 15 are inelectrical contact with one another as soon as the contacts 7 areinserted into the receptacle 2, and the electrical contact is maintainedwhile the cap is being twisted and locked, as heretofore described. Thusthis device can be used as an ordinary connector without locking theplug and receptacle if desired, or they can be locked together byturning either the plug or receptacle relative to the other.

An important feature of the device is that the contact fingers or bladecontacts of the plug or cap engage the contacts in the receptacle by therelatively longitudinal movement of the cap and receptacle as thesecontact fingers are inserted into the receptacle to thus close theelectric circuit, and this engagement and the electrical connection ismaintained in all subsequent relative movements between the cap andreceptacle both in turning the cap to bring the lugs on the blades intoalignment with the locking recesses in the receptacle and subsequentlongitudinal movement to seat these lugs in the recesses. That is, thereceptacle contacts are of sufficient width at their upper or free endportions to maintain this electrical contact and engagement during therelative turning movements. The same result is secured during thereverse movements to unlock and release the cap. Thus arcing in makingand breaking the electrical connection is reduced to a minimum, as thecircuit is not made or broken during the relative turning movements butis always made and broken on the relative longitudinal movements betweenthe members, which are quicker movements and thus less liable to causearcing.

Having thus set forth the nature of my invention, 1 claim:

1. An electrical connector comprising: an insulating receptacle body; aplurality of stationary contacts carried within said body; saidreceptacle body being provided with an end wall having a plurality ofcurved slots leading to said stationary contacts; a plurality ofinwardly facing recesses formed in said wall and opening on the innerside thereof; each of said recesses being spaced laterally respectivelyfrom one end of one of said slots; a detachable cap body having aplurality of elongated contact fingers for selective insertion into andthrough said slots to engage said stationary contacts by relativelongitudinal movement of said cap and receptacle bodies; said slotsbeing of a length to permit movement of said contact fingers in saidslots by relative turning movement of said cap and receptacle bodies;said contact fingers having their free end portions widened and beingprovided with laterally spaced projecting lugs which are arranged toextend outwardly relative to said receptacle body and seat in saidrecesses to lock said cap and receptacle bodies against relative turningmovement and separation when said bodies are connected; and spring meansdisposed within said receptacle body comprising a plurality ofindividual springs that are disposed in said receptacle body toindividually engage the free ends of said contact fingers and bias themand said cap body outwardly to seat said lugs in said recesses andretain them therein to lock said cap body against turning relative tosaid receptacle body; said lugs being movable to and from said recessesto lock and release said cap and receptacle bodies by relativelongitudinal and turning movements; said stationary contacts and saidcontact fingers being of a width such that they are in engagement tomaintain electrical connection between them throughout such movements.

2. An electrical receptacle comprising: an insulating body carrying aplurality of stationary contacts within it; said receptacle bodyincluding an end wall provided with a plurality of curved slots arrangedto allow the entrance of a plurality of contact fingers of a detachablecap as a result of relative longitudinal movement between the cap andsaid receptacle body to permit the contact fingers to engage saidstationary contacts; said end wall provided with a plurality of recessesopening on its inner side, each of which is spaced laterallyrespectively from one end of one of said slots; said recesses arrangedto receive locking lugs on the contact fingers to lock the cap and saidreceptacle body against relative turning movement; spring meanscomprising a plurality of individual springs disposed in said receptaclebody in alignment with said slots and arranged to individually engagethe free ends of the contact fingers when the latter are insertedthrough said slots and to thereby bias them and the cap outwardlyrelatively to said receptacle body to seat and retain the locking lugsin said recesses to thereby lock the cap and said receptacle bodyagainst relative turning movement.

3. An electrical connector comprising: an insulating receptacle body; aplurality of stationary contacts carried within said receptacle body;said receptacle body being provided with an end wall having a pluralityof curved slots leading to said stationary contacts; at least one recessformed in said end wall opening on the inner side thereof and spacedlaterally from one end of one of said slots; a detachable cap bodyhaving a plurality of elongated transversely curved contact fingersadapted to be inserted into and through said slots to engage saidstationary contacts by longitudinal movement of said cap body relativeto said receptacle body; said slots being of a length to permit movementof said contact fingers therein by relative turning movement of said capand receptacle bodies; said contact fingers provided with widened freeend portions; at least one of said contact fingers having a laterallyspaced projecting lug which extends outwardly relative to saidreceptacle body and seats in said recess to lock said cap and receptaclebodies against relative turning movement and separation when they areconnected; and spring means comprising a plurality of individual springsdisposed in said receptacle body in alignment with said slots andarranged to individually engage the free ends of said contact fingerswhen the latter are inserted through said slots to thereby bias them andsaid cap body outwardly relative to said receptacle body to seat andretain said locking lug in said recess to thereby lock said cap andreceptacle bodies against relative turning movement.

References Cited in the file of this patent UNITED STATES PATENTS1,669,549 Benjamin May 15, 1928 2,027,730 Hirmann Jan. 14, 19362,069,238 Fraser Feb. 2, 1937 2,102,625 Hubbell Dec. 21, 1937 2,451,982Scot Oct. 19, 1948 2,871,456 Healy Jan. 27, 1959

